HDAs of DNA or Oligonucleotides have many applications in the biological fields such as genetic research or diagnostic purposes. Conventional HDAs may have well over hundreds or thousands of different compounds (e.g., DNA, oligonucleotides, proteins, etc.) typically deposited on the surface of a substrate (e.g., a glass slide) in an array configuration.
Performing HDA inking and printing operations require a conventional HDA print head and its components to perform many repeatable motions, typically in the range of several million with a traveling distance in the range of 2 to 5 mm. A desirable range of accuracy and repeatability for conventional HDA print heads and their components should be within the range of +/−2 μm. In addition, the movements of the conventional HDA print head and its components should ideally be smooth. Utilizing precision ball raceways in a conventional HDA print head to attempt achieving such accuracy and repeatability is not a viable solution due to the prospective effects of local wear and brinelling.
Some conventional HDA print heads, such as a compound double bridge print head mechanism, have attempted to address the above-noted issues. However, these conventional HDA print heads are heavy and often involve a complex and costly manufacturing process. Moreover, their heavy weight may make them difficult to use. Referring to FIG. 1, a conventional HDA print head mechanism 10 having a conventional flexure 12 is shown. One of the disadvantages of the conventional HDA print head mechanism 10 includes having a large orthogonal displacement Δ, where Δ=1(1−cos α) and h=1(sin α). Having a large orthogonal displacement Δ increases the likelihood that a conventional HDA pin plate (not illustrated) situated within the conventional HDA print head mechanism 10 will become misaligned with respect to a conventional HDA reservoir structure 14 or a printing substrate (not illustrated) while inking and printing operations are performed. Such misalignments may damage the HDA print head mechanism 10, conventional HDA reservoir structure 14 or the printing substrate.
Referring to FIG. 2, a conventional HDA reservoir structure 14 and conventional HDA pin plate 16 are illustrated. Conventional HDA reservoir structure 14 includes conventional capillaries 18 having openings thereto on the conventional HDA reservoir top surface 15 facing conventional HDA pin plate 16. Conventional HDA pin plate 14 includes conventional pins 20 arranged in a pattern, which enter conventional capillaries 18 to pick up liquid materials 22 to subsequently transfer to a printing substrate (not illustrated).
Referring to FIGS. 3-5, an inking and a printing operation using conventional HDA pin plate 16 for transferring liquid materials 22 from conventional HDA reservoir structure 14 to a slide 24 will be described. The inking and printing operations ought to be performed within a short period of time of each other. Referring to FIG. 3, an inking operation includes using conventional HDA pin plate 16 to pick up liquid materials 22 from conventional HDA reservoir structure 14. Each of the conventional pins 20 must be positioned initially over a center of an opening of each conventional capillary 14. Achieving precise transfers of liquid materials 22 from conventional HDA reservoir structure 14 to each conventional pin 20 requires moving and/or positioning conventional HDA pin plate 16 to achieve and maintain a parallel orientation with respect to conventional HDA reservoir structure 14 throughout the inking operation.
It is important that conventional HDA pin plate 16 achieves and maintains a parallel alignment with respect to conventional HDA reservoir structure 14 because the internal linings or walls of the conventional capillaries 18 are typically thin, varying in thickness from 25 to 30 μm. A misalignment during an inking operation could cause conventional pins 20 to come into contact with the internal linings or walls of the conventional capillaries 18 and damage the conventional pins 20 and/or conventional capillaries 18, potentially costing thousands of dollars to replace. Conventional HDA pin plate 16 is lowered towards conventional HDA reservoir structure 14 until each conventional pin 20 enters its corresponding conventional capillary 18 and contacts liquid materials 22 held therein. Once each conventional pin 20 makes contact with liquid materials 22, conventional HDA pin plate 16 is retracted upwards and away from conventional HDA reservoir structure 14, and a reproducible portion of liquid material 22 is collected by each conventional pin 20.
Referring to FIG. 4, a printing operation includes using conventional HDA pin plate 16 to transfer liquid materials 22 to slide 24. Conventional HDA pin plate 16 is lowered until each conventional pin 20 is close enough for the liquid materials 22 to make contact with slide 24. Conventional HDA pin plate 16 must achieve and maintain a parallel alignment with respect to slide 24 throughout the printing operation to avoid damage, since the conventional pins 20 must not make direct contact with slide 24. Slides 24 are manufactured out of a glass material approximately 1 mm thick. A misalignment could cause some of the conventional pins 20 to come into contact with slide 24 before other conventional pins 20 are close enough to deposit liquid materials 22, resulting in damaging conventional pins 20. Further, remnants of damaged conventional pins 20 could contaminate the liquid materials 22 and damage the internal linings or walls of the conventional capillaries 18 during subsequent inking operations. Again, the damage could result in costing thousands of dollars since the liquid materials 22 are often expensive. Once all the liquid materials 22 are transferred to slide 24, conventional HDA pin plate 16 is retracted upwards away from slide 24.
Previously, a manual, five-axis and one radial micromanipulation has been needed to align conventional HDA pin plates 16 with respect to conventional HDA reservoir structures 14 to perform accurate and precise inking and printing operations and to avoid the types of damage mentioned above. To perform such a micromanipulation, conventional HDA pin plate 16 and conventional HDA reservoir structure 14 are situated within a conventional print head such as the conventional HDA print head mechanism 10 mentioned above with respect to FIG. 1. Such a conventional print head secures the conventional HDA reservoir structure 14, and eventually the slide 24, to allow the conventional HDA pin plate 16 to be moved and/or positioned during the micromanipulation before performing inking and printing operations.
Referring to FIG. 5, micromanipulation for alignment purposes involves moving and/or positioning conventional HDA pin plate 16 along the X and Y axis and the θ radius to achieve planar superposition with respect to the conventional HDA reservoir structure 14. The conventional HDA pin plate 16 is moved and/or positioned in the direction of the α and β axis to achieve spatial orientation with respect to conventional HDA reservoir structure 14. To determine whether conventional HDA pin plate 16 is oriented parallel with respect to conventional HDA reservoir structure 14, conventional HDA pin plate 16 may be visually observed to determine whether each conventional pin 20 has entered each corresponding conventional capillary 18 of conventional HDA reservoir structure 14. Referring back to FIG. 3, the micromanipulation with regard to the X and Y axis and the θ radius is accomplished by observing the crossed stages of the X and Y axis and the θ radius with respect to each conventional pin 20 and the meniscus level of liquid materials 22 present in each conventional capillary 18, assuming conventional pins 20 are at least partially transparent.
The micromanipulation with regard to the α and β axis can be very difficult to perform since it often undermines the micromanipulation with regard to the X and Y axis and the θ radius, as well as for other reasons. For instance, each time an inking and printing operation is performed, conventional HDA pin plate 16 must be replaced in the conventional print head by a fresh conventional HDA pin plate 16. Thus, several conventional HDA pin plates 16 are typically prepared prior to performing inking and printing operations, depending upon the number of slides 24 expected to be printed on, requiring the above-described micromanipulation to be performed for each one. Moreover, performing the above-described micromanipulation process typically takes at least one hour per conventional HDA pin plate 16. Further, the removal and installation of conventional HDA pin plates 16 from conventional print heads often require special tools. Therefore, it is rather time consuming and difficult to install and remove conventional HDA pin plates 16 from conventional print heads. Moreover, aligning conventional HDA pin plates 16 with respect to conventional HDA reservoir structures 14 is also time consuming and tedious.
Furthermore, conventional HDA pin plates 16 are vulnerable to damage resulting from misalignments during the inking and/or printing operations as mentioned above. Thus, additional conventional HDA pin plates 16 are typically prepared prior to performing inking and printing operations since it would be undesirable to halt operation of the conventional pin heads for the at least one hour needed to prepare a replacement conventional HDA pin plate 16 by performing a tedious micromanipulation each time a conventional HDA pin plate 16 was damaged. Typically, at least ten more additional conventional HDA pin plates 16 than are actually needed are prepared prior to performing inking and printing operations.